Concurrent Accumulation of Myricetin and Gallic Acid Putatively Responsible for the Umami Taste of a Specialized Old Oolong Tea

Feng-Yin Li¹, Wei-Hung Yang^{2, 3}, Chi-I Chang⁴, Sin-Jie Lee², Chih-Chien Hung¹, Ying-Jie Chen², Tzyy-Rong Jinn^5, and Jason T.C. Tzen^{1, 6,}

¹Department of Chemistry, National Chung-Hsing University, Taichung, Taiwan, R.O.C

²Graduate Institute of Biotechnology, National Chung-Hsing University, Taichung, Taiwan, R.O.C

³Taichung Hospital Department of Health, Taichung, Taiwan, R.O.C

⁴Graduate Institute of Biotechnology, National Pingtung University of Science and Technology, Pingtung, Taiwan, R.O.C

⁵School of Chinese Medicine, China Medical University, Taichung, Taiwan, R.O.C

⁶School of Chinese Medicine, China Medical University, Taichung, Taiwan, R.O.C;Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan, R.O.C

Cite this paper:
Feng-Yin Li, Wei-Hung Yang, Chi-I Chang, Sin-Jie Lee, Chih-Chien Hung, Ying-Jie Chen, Tzyy-Rong Jinn and Jason T.C. Tzen. Concurrent Accumulation of Myricetin and Gallic Acid Putatively Responsible for the Umami Taste of a Specialized Old Oolong Tea. Journal of Food and Nutrition Research. 2013; 1(6):164-173. doi: 10.12691/jfnr-1-6-8

Abstract

Strong umami taste was perceived in a specialized old oolong tea reproducibly converted from a fresh oolong tea by fierce baking biannually for five years. Phenolic compounds in this umami tea and those in an initial fresh oolong tea were analyzed and compared. The results implied that the abundant catechin derivatives and flavonol glycosides were significantly reduced while three compounds were evidently accumulated after the tea conversion. These three compounds were chemically identified as gallic acid and two correlated flavonols, myricetin and quercetin. Molecular modeling suggested that myricetin and gallic acid might serve as ligand and enhancer to activate the umami receptor synergistically. Binary docking of myricetin and gallic acid induced the gate closure of the binding cavity in the umami receptor, in a manner similar to that of glutamate and its enhancer, inosine 5′-monophosphate. Regardless the induced fitness, the detailed molecular interactions between these two sets of binary components and the receptor were drastically different. In this binary docking modeling for umami taste, myricetin could not be equivalently replaced with any of the major tea phenolic compounds.

Keywords:
gallic acid myricetin old oolong tea quercetin umami

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References:

[1]	Haslam, E. “Thoughts on thearubigin” Phytochemistry, 64(1), 61-73, 2003.
[2]	Lee, V. S. Y., Chen, C. R., Liao, Y. W., Tzen, J. T. C., and Chang, C. I. “Structural determination and DPPH radical scavenging activity of two acylated flavonoid tetraglycosides in oolong tea (Camellia sinensis)” Chemical & Pharmaceutical Bulletin, 56(6), 851-853, 2008.
[3]	Sang, S., Lambert, J. D., Ho, C. T., and Yang, C. S. “The chemistry and biotransformation of tea constituents” Pharmacological Research, 64(2), 87-99, 2011.
[4]	Chandrashekar, J., Hoon, M. A., Ryba, N. J., and Zuker, C. S. “The receptors and cells for mammalian taste” Nature, 444, 288-294, 2006.
[5]	Ghirri, A., and Bignetti, E. “Occurrence and role of umami molecules in foods” International Journal Food Sciences and Nutrition, 63, 871-881, 2012.9.
[6]	Mouritsen, O. G. and Khandelia, H. “Molecular mechanism of the allosteric enhancement of the umami taste sensation” the FEBS Journal, 279, 3112-3120, 2012.
[7]	Behrens, M., Meyerhof, W., Hellfritsch, C., and Hofmann, T. “Sweet and umami taste: natural products, their chemosensory targets, and beyond” Angewandte Chemie (International ed. in English), 50 (10), 2220-2242, 2011.
[8]	Nakagawa, M. “Contribution of green tea constituents to the intensity of taste element of brew” Journal of Food Science and Technology, 22, 59-64, 1975.
[9]	Horie, H., Ujihara, T., and Kohata, K. “Analysis of tasty nucleotides in green tea infusions (in Japanese)” Tea Research Journal, 93, 55-61, 2002.
[10]	Kaneko, S., Kumazawa, K., Masuda, H., Henze, A., and Hofmann, T. “Molecular and sensory studies on the umami taste of Japanese green tea” Journal of Agricultural and Food Chemistry, 54(7), 2688-2694, 2006.
[11]	Kuo, P. C., Lai, Y. Y., Chen, Y. J., Yang, W. H., and Tzen, J. T. C. “Changes in volatile compounds upon aging and drying in oolong tea production” Journal of the Science of Food and Agriculture, 91, 293-301, 2011.
[12]	Lee, V. S. Y., Dou, J., Chen, R. J. Y., Lin, R. S., Lee, M. R., and Tzen, J. T. C. “Massive accumulation of gallic acid and unique occurrence of myricetin, quercetin and kaempferol in preparing old oolong tea” Journal of Agricultural and Food Chemistry, 56(17), 7950-7956, 2008.
[13]	Dou, J., Lee, V. S., Tzen, J. T. C., and Lee, M. R. “Identification and comparison of phenolic compounds in the preparation of oolong tea manufactured by semifermentation and drying processes” Journal of Agricultural and Food Chemistry, 55(18), 7462-7468, 2007.
[14]	Yang, S. C., Fang, J. M., and Cheng, Y. S. “Chemical constituents from the root and aerial parts of Rosa taiwanensis” Journal of the Chinese Chemical Society, 42, 573-577, 1995.
[15]	Sawai, Y., Moon, J. H., Sakata, K., and Watanabe, N. “Effects of structure on radical-scavenging abilities and antioxidative activities of tea polyphenols: NMR analytical approach using 1,1-diphenyl-2-picrylhydrazyl radicals” Journal of Agricultural and Food Chemistry, 53(9), 3598-3604, 2005.
[16]	Matsuda, H., Higashino, M., Chen, W., Tosa, H., Iinuma, M., and Kubo, M. “Studies of cuticle drugs from natural sources. III. Inhibitory effect of Myrica rubra on melanin biosynthesis” Biological & Pharmaceutical Bulletin, 18(8), 1148-1150, 1995.
[17]	Syu, K. Y., Lin, C. L., Huang, H. C., and Lin, J. K. “Determination of theanine, GABA, and other amino acids in green, oolong, black, and Pu-erh teas with dabsylation and high-performance liquid chromatography” Journal of Agricultural and Food Chemistry, 56, 7637-7643, 2008.
[18]	Zhang, F., Klebansky, B., Fine, R. M., Liu, H., Xu, H., Servant, G., Zoller, M., Tachdjian, C., and Li, X. “Molecular mechanism of the sweet taste enhancers” Proceedings of the National Academy of Science of the United States of America, 107(10), 4752-4757, 2010.
[19]	Kunishima, N., Shimada, Y., Tsuji, Y., Sato, T., Yamamoto, M., Kumasaka, T., Nakanishi, S., Jingami, H., and Morikawa, K. “Structural basis of glutamate recognition by a dimeric metabotropic glutamate receptor” Nature, 407(6807), 971-977, 2000.
[20]	Muto, T., Tsuchiya, D., Morikawa, K., and Jingami, H. “Structures of the extracellular regions of the group II/III metabotropic glutamate receptors” Proceedings of the National Academy of Sciences of the United States of America, 104(10), 3759-3764, 2007.
[21]	Brooks, B. R., Bruccoleri, R. E., Olafson, B. D., States, D. J., Swaminathan, S., and Karplus, M. “CHARMM: A program for macromolecular energy, minimization, and dynamics calculations” Journal of Computational Chemistry, 4(2), 187-217, 1983.
[22]	Chen, Y. J., Kuo, P. C., Yang, M. L., Li, F. Y., and Tzen, J. T. C. “Effects of baking and aging on the changes of phenolic and volatile compounds in the preparation of old Tieguanyin oolong teas” Food Research International, 53, 732-743, 2013.
[23]	Dou, J., Lee, V. S., Tzen, J. T. C., and Lee, M. R. “Rapid identification of acylated flavonol tetraglycosides in oolong teas using HPLC-MSn” Phytochemical Analysis, 19(3), 251-257, 2008.